When avocado fails early in the process (for example in
_setup_environment_variables) it crashes, because the test status is
None. Other example could be user-defined status, which is not inside
user-facing-statuses.

This patch modifies the "status" to "ERROR" when test reports
unsupported status and sets related values to provide details regarding
this failure.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>